I have been renting out power quality meters/loggers since 1987. Some advice.
Always try to encourage your customer to rent you or a person familiar with meter to setup, install, verify that meter is logging correctly, download, and produce report. Nothing is as bad as finding a months worth of data is trash because a current probe is installed backwards.
Build into your quote contingency fees if your access / installation / removal is delayed through no fault of your own. I don’t know how many times I have been cooling my heels because the contractor was late for the installation or the customer couldn't shut down equipment, because some IT person hadn’t read a memo.
if metering is time sensitive, plan one returning a couple of days after installation to verify that data is being logged correctly.
Always make sure that your equipment is protected. Elevated off the floor and oriented so that water cannot damage. Positioned that connectors are protected from physical damage.
Murphys law states that the longer you have to travel to the job-site, the more problems you will have. I always try to carry extra meters, probes, leads, power cords, laptop, and laptop connection cable.